This policy controls what version of the Microsoft .Net Framework is used for hosting managed code in worker processes launched ...

This policy controls what version of the Microsoft .Net Framework is used for hosting managed code in worker processes launched by the System Center Management Service.
      
This policy only applies to agents and not management servers.  Management servers may not have the .Net Framework version setting modified.

The default value if this policy is not specified is to use the Microsoft .Net Framework 2.0 if the agent is running on a Windows 7 or older operating system.  If a version of Windows newer than Windows 7 is used the Microsoft .Net Framework 4.0 is the default.